Same problem as some others here but there have never been a real answer.

I followed all the instructions and installed midiyoke. I can see a light in reason when I hit the keyboard but I cant here a sound. If I switch midi out to my soundcard I can hear it again. If I switch back to midiyoke 1 there is no sound?

What should I do to hear the sounds in reason when I play the keyboard???

the problem is that here it works! so I wouldn't know how to fix a problem that I cannot reproduce. Once crucial step is to activate "play in background" (or what it's called) in Reason, as indicated in the tutorial. If you don't, Reason will stop any sounds when you switch to another application (i.e. Mouse Keyboard).

Also, you probably need to "connect" the MIDI IN in Reason to a synthesizer in Reason, and possibly create a MIDI track in the sequencer, which uses that MIDI port.